The present invention relates to plastic bottles used for storing and dispensing thick, viscous liquids and, more particularly, in a plastic bottle having a closed body of a squeezable plastic attached to a cylindrical neck portion, to the improvement to provide ease of dispensing thick, viscous liquids while preventing the drying and thickening thereof comprising, a thin-walled, plastic, liquid-containing bag inserted into the body and attached about an inner periphery of the neck portion; and, valve means positioned between the atmosphere outside of the bottle and a space between the body and said bag for permitting air to flow into said space but not out of said space.
Since their availability, plastic bottles, such as that generally indicated as 10 in FIG. 1, have been employed with great favor in the storing and dispensing of liquids. The bottle 10 typically comprises a body portion 12 with a threaded neck portion 14 projecting upward therefrom. In this regard, the plastic bottles 10 are substantially identical to the glass bottles that they replaced for many uses. Being of plastic, however, they provide many attributes that their glass predecessor do not. For one, they bounce when dropped in the shower, tub, or the like. This makes them much safer for the holding and dispensing of thick, viscous liquids like shampoo, hair conditioner, and the like. Moreover, as illustrated in FIG. 2, they have the additional benefit of being squeezable. When the bottle 10 is inverted and its sides squeezed as symbolized by the arrows, the incompressible liquid 16 therein is forced from the bottle. Because of this feature, many bottles have caps that do not have to be removed from the threaded neck 14 in order to dispense the liquid 16. These caps have tip to activate valves or flip on/off coverings over a dispensing hole.
Prior art plastic bottles such as 10 work well when they are full; however, as the liquid 16 in the bottle 10 diminishes, so does the acceptable performance. By the time the condition of FIG. 3 exists, so do problems in getting the liquid 16 out of the bottle 10. For one thing, the amount of the liquid 16 and, therefore, the weight of it is small. Moreover, the amount of air 18 above the liquid 16 is great. This is very often exacerbated by the user leaving the top in a open state at all times so that the air 18 is open to the atmosphere. As a result, the liquid 16 tends to dry out and thicken beyond its original thick, viscous state; that is, it becomes even thicker and less prone to "flow". In the extreme, it becomes the consistency of Jello. As all this takes place, the user finds the dispensing process becomes like that illustrated in FIGS. 4-7. When the bottle 10 is inverted for use, the liquid 16 starts to slowly leave the bottom of the bottle 10 under the force of gravity (FIG. 4). It moves slowly down the side of the bottle 10 towards the neck 14 (FIG. 5). It finally reaches the neck end of the bottle 10; but, until it closes the hole leading out of the neck 14 all the squeezing in the world does not help (FIG. 6). Finally, it flows into the neck 14 and squeezing of the sides forces the liquid out the neck 14 (FIG. 7).
In a related area of the bottle art, it was a common problem in bottles used for dispensing baby formula, and the like, for the infant to ingest large quantities of air along with the formula when a nipple was attached to the neck portion of a bottle such as 10 in FIG. 1 (either in glass or plastic). To solve this problem, the two-part bottle 20 of FIG. 8 was introduced. Bottle 20 comprises a rigid cylindrical sleeve 22 which is open at the bottom. A thin plastic bag 24 is inserted into the sleeve 22, folded over the top edge, and held in place with a plastic or rubber nipple 26. The formula 28 is placed in the bag 24. As the infant sucks the formula 28 from the bag 24, air entering the open end of the sleeve is free to collapse the bag 24 about the formula 28. As a result, very little air, if any, is ingested by the infant during feeding.
Wherefore, it is an object of the present invention to provide a plastic bottle for the storing and dispensing of thick, viscous liquids which prevents the liquid from getting dried out and thick from air exposure as the bottle is emptied.
It is another object of the present invention to provide a plastic bottle for the storing and dispensing of thick, viscous liquids which allows the liquid to be pumped from the bottle by squeezing the sides as the bottle is emptied.
It is still another object of the present invention to provide a plastic bottle for the storing and dispensing of thick, viscous liquids which allows the liquid to be pumped from the bottle by squeezing the sides without having to wait for the liquid to slowly flow from the bottom to the top when the bottle is inverted.
Other objects and benefits of the present invention will become apparent from the description which follows hereinafter when taken in conjunction with the drawing figures which accompany it.